The No 1 characteristic of the automotive market today is the demand for reliable and economical vehicles. Health authorities the world over are imposing strict limitations on the toxicity of exhaust gases. These factors account for stringent requirements imposed on individual units and systems of vehicles, including the ignition and fuel injection systems. However, it is impossible to produce better vehicles only by improving the existing mechanical ignition distributors and fuel injection systems. The solution to the problem seems to be the use of electronic trigger pulse systems.
There is known a method for producing trigger pulses in relation to a preset phase of motion proceeding with a constantly variable period (cf. U.S. Patent No. 3,934,563), whereby a first control pulse is formed as a preset phase of the motion is reached, a second control pulse is formed as the phase of the motion is changed by a preset value which corresponds to a fundamental time interval, and pulses are accumulated, whereof the repetition frequency is at least one order greater than that of the control pulses, whereupon the accumulated pulses are counted until a preset number is reached, which moment marks the onset of a trigger pulse.
There is known a device for producing trigger pulses in relation to a preset phase of motion proceeding with a constantly variable period. The device is intended to carry out the foregoing method and comprises a control unit having its inputs connected to an initial adjustment pulse unit and a control pulse unit, whereas outputs of the control unit are connected to a main pulse counter and a main controlled frequency divider, respectively, which are interconnected. The main pulse counter has its output connected to a comparator. The main controlled frequency divider has its input connected to a pulse generator. The device further includes an auxiliary controlled frequency divider having its first input connected to the pulse generator, its second input connected to a load sensor, and its output connected to an auxiliary pulse counter whose output is connected to the comparator.
The aforesaid method and device have certain disadvantages. Between the start of integration of electric pulses and the instant a trigger pulse is produced, the phase of the motion changes considerably, for example, by 80.degree.; the acceleration of the periodic motion may be so high as to lead to an inevitable dynamic error in producing a trigger pulse.